#include<stdio.h>
#include<conio.h>
#include<ctype.h>

int sum();

main()
{
	int tot;
	tot = sum();
	if(tot == -1)
		printf("\nnot select!\n");
	else
		printf("\nthe result is: %d\n",tot);
}

int sum()
{
	int i,tot=0;
	char key;
	
	key = getche();
	if(key != '0' && key != '1')
		return (-1);
	for(i=(key=='0')?2:1 ; i<100 ; i+=2)
		tot+=i;
	return tot;
}
